Electric alarm system



W. S. LUDLOW, JR. ELECTRIC ALARM SYSTEM.

APPLICATION FILED MAY 6,1918.

Patented Mar. 28, 1922.-

111 VIII/0;

Q /{ll'arngs WALTER s. minnow, JR, or oInoINNA'rI, OHIO.

' ELECTRIC ALARM sis'rnm.

To all whom it may concern:

Be it known that L lVAL'rnR S. lrc'nnow, Jr., a citizen of the United States, and residing at Clncinnati, 1n the county of Harm .ilton and State-of Ohio, have invented a new and useful Improvement inElectric Alarm Systems, of which the following specification is a full disclosure. .7

My invention relates to a system for electric transmission of signals particularly adapted forcentral station watchmans time recording and fire'alarm service.

For this particular class of signal-service, single call boxes are used for both watchmans time recording or fire alarm signals,

the advantage being that the transmitting mechanism and connecting lines are tested with each watchmansreport signal to insure its being in order fortransmitting an emer gency or fire call. Thus constant check and I supervision is had and the apparatusis always ready for an'emergency. The signals from each box, whether report or fire sig nals, are received over the same apparatus at the central station, and although the signal indicating characters maybe distinguishable, there is nothing to particularly call the attendants attention quickly to an emergency or'fire call.

3O mitting device for the different species of:

With mylnvention I use the same transcalls, the advantage for regular testing of the lines and apparatus being maintained,

but the fire or emergency calls'iare received and recorded over a speclal'recelvmg appa-.

ratus in conjunction with the general receiving apparatus. The special receiving'apparatus' can be utilized for operating a sounder and also'transmittin'g the emergency calls to the fire or, police stations for direct notification service;

Therefore an object of the invention is to provide a central stationelectricjsignal' service system with a plurality of signal receiving devices selectively responsive for general or report calls and collectively responsive "for special or emergency calls with their op 'eration controlled and afiected by different current strengths or changes in current strength, so thatthe same impulse transmitting devices or call-boxes in circuit with the receiving devices may be used for the various kinds of signals and their character de-' termined or distinctively recognized by the particular receiving device or the number of them operating at the same time; "The curopen.

Specification of Letters mam. I P t' t dM r, 2 1 Application filed May 6, 1918. Serial No. 232,700..

rent strength is governed by resistancein the v circuit line or knee, controlled through the call-box from which and at the time the signalis being transmitted. c

' Another object is to'provide a signalserv-s ice system of a combined watchmans timereporting and fire alarm class vvitha plurality of signal receiving instruments, the receivers influenced each by 'difierentcurrent strength for a selective or combined response, enabling time reporting and firealarm calls to be sent; or transmitted from each call-box and'the character "of the call easily distinguished and'deterinined by the number of receivers responding or reporting the.

calls, and which adapts itself for'transmit' ting distinctive signals for the various kinds of calls from the samecall-box. v Other features and objects of the invention, combination of elements and'arrangements of parts, will behereinafter' more flully described, in. connection v with jtheac- 'compa'nying drawings, forming a parthe'reof. and more particularly pointed out in the'cla im, in the drawings] like characters of reference denote 'correspond1ng' parts throughout the several views, of ;ivhich:

Fig. l is a diagrammatic viewof a slgnal system conta ning my improvements in the simplest form, and ma systemhaving me tallic and earth return circuits, and inwhlch a common break wheel for eachcall transmits signals for general and special 51g n ficance.

Fig. 2 1s a"modifiedfform over Fig. 1,,

in which separate breakv Wheels for each call-box are'used to transmit the general and special calls. v o

Fig; 3is another modified view over Fig.

1,.in which two earthfre'turn circuitsare used, one normally closed and the :other As the system primarily is contemplated for a central station night watch tinnare-v portingand-recording and firm alarm signal service, the, description generally will beconfined' to this particular field of use,

although comprehending a wider field of use, wherein it 'maybedesired to transmit as to their character orfkind forlvarious service utility. Q I a The line. or field circuit or circuits may compare to those now generally prevailsignals distinguishable at a receiving point ing for watchmans reportmg and firc-v alarm service, as an all-metallic circuit'li ne approved in different localities.

, the -metallicline.

" iffering in} with divisional earth return circuits tothe central station or receiving point from each call-box, for normallytransmittlngtwo distinctive signals from each call-box or transmitting point, and the distinctive s gnals may be designated open and closed c1rcuit signals. The systems also include features for testing andestablishing a circuit in the event of break or ground trouble on The system mayalso be of.. a class in which two distinctive circuits, are established 5 for signal transmission, each circuit having an earth return tothe central stati0n 0rreceiving po1nt,.the1rece1v1ng relays in said circuit belng operative by a change in the current strength, and-alternateopen- I ing and closing of the clrcuit.

The same signal or, break wheels may be utilized for bothgeneral and special signails or separate break wheels rotating as a unit for-each, Within the aspects of this invention. In the-latteninstance, however, it ispreferable to. cut off the one during the active or transmitting, period of the other toavoid a confusion of signals on. any and all of the receiving relays. I i

As systems ofthis class :niust to a degree' meet andflcom 1y with rules and reuirements re'ard as license regulations,

wiring arrangement or Scheme-cannot be universally followed and which primarily is duevto the various kinds or styles of transmlttin'g apparatus a recommended and "Thus, the different modifications of sys- V terns illustrated "in the drawings follow those mosticommonly' prevailing and. gen erally. approvedstandards with which my improvements are readily combined.

" eferringto Fig. l'o'f tliedrawings, 1, 2,

- 3,indicate,signal receiving relays each of a ltactsB and" 7, in contacts serves as v A retractile spring rovidedtfor moving the common type comprising an. electr0magnet coil 4, armature 5, [swinging between consome instances one of the an adjustable stop pin. 8, regulatable at 9, is

armature away rom the electro-magne't. On' the energizing 'o'f'the electro-magnet, provided the resistance of the spring 8 is not greater than the pull of theim'agnet, attraction ,ofits armature closes the contact 6,

completing the circuit of a local battery or generator lead-v ing to and} connecting with signal printing or 'recordin g apparatus, for controlling and operating 'sai'd apparatus. y jRelay.1 1 imayb designated as avprime or firstrelayfrelayfl as a supplemental or second, having "the tension of its spring -8 set to atenslon so as torequire a different on increasein the current strength over that "required "for "relay 1, for its-'eleetro-rnagnet "e tm siermafiu v riiferent localities, a definite from another, whether Likewise relay 3 is set to require an increase in current strength over both relays 1 and 2beforeits'electro-inagnet will atand 3 are connected in series with one another and thus under a normally closed c1r-. cuit, relay 1 will stand with Y its armature ,tractj its armature lever. The relays l, 2

leverattractedto its electro-magnet, while relays 2 and 3 will stand open or with their armature levers in a retracted-positionaway from their electro-magnets.

10 indicates a combined watchinans and fire-alarm. call-box Y of which there may. be

any number connected in'ser'ies andior tlie present purposes only one of' such boxes is included in the system. V V

These call-boxes, as far as tl'ieiricont-rol or method of operation'forsending ac'alI is concerned, correspond to those now in .com-

of break wheel, pyelesW'i-ll be had. 'Thus a single breakwheelmaybe employedand the class ofsignal oncallfdis- I 1 10o tinguishedl at the receiving point :by rule number Off timesthe signalis-jtransmitted.

a-break or signal fwheelrand The principle of diiferentlal breakwheel cycle for distinguishing one kindiotasig-nal, different break wheels are employed, is'utilized in thezvarious modifications. herewith included as a part of this specification.

indicates lthe clock mechanism opera-ted in one instance by a key ll fonone kind or general call. and by. the p'ull lever '13 fQIf a stood that with the key control thelbreak j wheel 14 is given one: revolution and with the pull lever control, the break wheel is given a plurality ofrevolutions,-a;nd for the present purposes, say three revolutions.

The pull levermay, call-boxes, their, general-details of constructiongare well ias in-some .types ,of

v known and understood in the art; no-specific '7 disclosure need be made herein. Three flexible contactfingers one or a plurality of be. automatically reset, but as Now continuing to refer=to -Figbi1, :12

second kind or special call, 5 it being underrelatively. arranged and insulatedfrom one another with the-intermediate finger "16; ex-

tendeds'to engagezthe peripheryhfthe break 7 wheel'lt, so asto bemovable.to alternately make; contact with fingers 15?;an'd 317. f The break wheel 14 ishotched or toothed 1 fora V properfinger control, to" transmit a ,definite 9 control through the-operation the pull lever; a plurality signal by making and breaking the open and" closed circuits to each break wheel cycle or with the receiving pointor station. The V pull'lever 13 connects with a contact member 19, making contact with a contact t erminal 20. The contact terminal 20 connects through a wire 21, with thewire 22,. connecting with the break finger 15. The wire 22 connects with one poleof the resistance 23 and the opposite pole of the resistance connects with the wire 24:, leading to the ground 25. A Wire 26 connects wire 24 with the said member 19. condition of the system, the switehrmem'ber 19 stands open, so that the resistance connects in circuit with the break finger 15 and the resistance is shut or cut out of circuit when the switch member 19 is closed, and a closing of the switch member-19 is accomplished when operating the pull lever 13.

The relays 1, 2 and 3 located in a central. serial station or receiving point have their electro-magnets connecting in series with each other and connect through a wire 27 with the break finger 16. The relays from an opposite pole connect'with a resistance 28 and one terminal or pole of the battery or generator 29. The opposite pole of the battery or generator 29-has a ground. lead 30 and also connects with the fieldwire line 31, which includes in series therewith a resistance 32, and said field line 31 connects with the break finger, 17 of the last call-box of the series in'the system, and the fingers 16 and 17 of all of the call-boxes connect in series through one another to close or. connect field wire 27 and 31.

It should be observed that the metallic line provides a' normally closed circuit under which relay 1 has its armature attracted, and relays 2 and 3 have their armature levers in a retracted position, their electroanagnets are energized, but the current strength by reason of the resistance 28 and 32, is lowered so that the energizing pull of the electromagnets 2, 3, is not great enough to counteract the pull of the springs of the armaturesof the relays 2, 3. a

For a general or watchmans signal, a

break wheel 14: is rotated, which for signal.

transmission makes and breaks the circuit through fingers 16 and 17, and also makes and breaks the circuit through fingers 15 and 16. When the fingers 15 and 16 are brought into contact with each other, thecircuit has an earth return from the call-box,

and is completed through. the following course From the relays 1, 2, 3,'field line 27 ,contact fingers 16, 15, wire 22, resistance 23, wire .24, ground 25, through the earth to Under normal pull lever 13. l

ground'leacl 3 ,.generator 29, resistance 28 and opposite pole of relays 1, 2, 3, connected in series. 17

During suchperiochi the metallic line 31 and the resistanceit carries, is cutout-sol that the strength of current passing through the 'electro-magnets of the relays-is increased and to a degree increases the magnetic pull of the electro-magnet of relay 2', and-attracts its armature,overcoming the resistance of the spring tension. 7 Relay 3, howeyer,will not be affected, because the circuit still carries sufiicientresistance, preventing its magnet from exerting a pull sufiicient to-overcome the resistance of the spring connectingwithits armature. This can only be eliminated by cutting out the resistance 23 and which can only be accomplished through the For transmitting aspecial or fire-call, the pull lever 13 is thrown, to start or crank the clock mechanism. Such operation closes switch 19, with contact 20, shunting or cutting out the resistance 23 in the earth return of the circuit, whereupon when break fingers 16 and 15 are in contact, relay 3 will attract its armature lever and respond to the signal impulses in conjunction with relays 1 and 2.

Therefore for a general alarm, relays 1 and 2 are operated and for a special alarm, relays 1, 201' 3, or all are operated, each receiving the same signal, but when" relay 3 recognizes that a special or fire signal is ,be-

'ing transmitted, although the signal number or indication is the same for either general or special alarms.

' Themodification shown in Fig.2 employs a. special signal break-wheel 33 rotatingas a unit Withthe general break-wheel 14:. It

will be observed that the switch member 19 alternately engages with two contact terminals 20 and 20% Terminal 20 connecting with the break'finger 15 of the general break finger 14, through a wire 22, which includes the resistance 23 in series therewith, while contact terminal 20 connects witha wire 34 leading to and connecting with a break fin-- ger 35 of the special break wheel 33. The finger 35 makes contact with finger 16 engaging. break-wheel 33 and is in circuit connection with the field line 27 and to which finger 16 of the general call break-wheel 14 connects. A control of signal transmission from either general call break-wheel 14: or special call break-wheel 33 is through the relative position of the pull lever 13. For general calls, the break fingers 35 and 16 are cut out of circuit, while for a special call, the break fingers of the general call break-wheel 14 are cut out of circuit and likewise the resistance 23. In this form, the general and special calls are distinctive of one another.- Rerelay 3 responds with the others-when the call is made upon throwing the pull lever 13. The control and operation of the break wheels are substantially the same as that described in the form illustrated in Fig. 1.

-one of said two devices, and meansiorshunting out said second resistance and thereby allow the transmission of: signal impulses which will operate all of the signal The system diagram, shown inFaig. 3, may be regarded assubstantially the same as that Y in Fig. 2, except thatthe two circuit lines each have an earth return, nocomplete inetallic circuit being employed.

f Having describedmy invention, I claim:

Aslgnahng system comprisinga normally closed metallic circuit, I a plurality of signal receiving electrical devices connected VIII seriesin the signaling circuit, thesaid de qvices being'responslve to relatively dlfi'erent strengths of ele'ctric current, a resistance in the c1rcu1t rendering two of said devices nor- "a ground returncircuit front-the cttll box to the receiving devices, inqludinga second resistance and shunting out of the saldfirst resistance, means for transmitting signal "impulses through theground circuit to operate receiving devices;

ing'; witnesses.

WALTER sfiLUDLoWfJR.

WVitnesses: r V l :D DRAUHENBERG V .L .A BECK.

V t .30 "InxWitne'sswhereof,I hereunto subscribe my name. as attested bythe' two' subscrib- 

